Question

I’m hoping to count how many times a pointer is being used. I have a map:

static std::map<unsigned int, unsigned int> counters;

When I want to insert a new value to it i’m using it like this:

template<class T>
MyClass::addPointer(T * tPtr){
    counters[((unsigned int) tPtr)]++;
}

Is it OK and safe to do a cast like this? It’s not an expensive operation etc.?

Also, is this a suitable way to ensure each pointer only gets one count?

Thanks

Answer 1

IMO, you really don’t need to cast it to unsigned int. You can have the map with void*:

static std::map<void*, unsigned int> counters;

Also a null check is important here:

template<class T>
MyClass::addPointer(T * tPtr){
  if(tPtr != 0)
    counters[tPtr]++;
}

Rest is fine.